minor #8152 Update data.rst.inc (AndrewDBattye)

This PR was submitted for the 2.8 branch but it was merged into the 2.7 branch instead (closes #8152).

Discussion
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Update data.rst.inc

No need for an apostrophe.

Commits
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35384f3 Update data.rst.inc

Author: xabbuh

reference/forms/types/options/data.rst.inc

@@ -17,5 +17,5 @@ an individual field, you can set it in the data option::
 
     The ``data`` option *always* overrides the value taken from the domain data
     (object) when rendering. This means the object value is also overriden when
-    the form edits an already persisted object, causing it to lose it's
+    the form edits an already persisted object, causing it to lose its
     persisted value when the form is submitted.